Stopper for sealing containers

ABSTRACT

A stopper for sealing a container having an annular lug inwardly projecting at the edge of the container opening portion, comprising a resilient, cylindrical stopper body provided spatially from the upper end thereof with an annular groove engageable with said lug.

United States Patent Ikeda et al. 1 Aug. 5, 1975 [5 STOPPER FOR SEALINGCONTAINERS 3.362.556 1/1968 Waldrum 215/355 x 3.682.597 8 1972 H h 23259 [75] Inventors: Tatuhiko lkeda, Funabashi, Japan; use

Jintan Terumo Co., Ltd., Tokyo. Japan FOREIGN PATENTS OR APPLICATIONS[73] Assignee; 801,540 12/1968 Canada 215/355 3 .I 2 5 3. Filed: p 91974 1,172, 48 11/1969 United Kingdom 1 55 [2]] Appl' 462510 PrimaryExaminer-R. E. Serwin Attorney, Agent, or Firm-Kemon, Palmer & [30]Foreign Application Priority Data Eswbmok Apr. 23, 1973 Japan 48-47564[57] ABSTRACT [52] US. Cl. 23/259; 23/292; 215/355:

215/1316 3 A stopper for sealing a container having an annular [51] Int.Cl. G01N 1/10; B65D 39/00 l g inw r ly projecting at the edge of thecontainer [58] Field of Search 23/292, 259, 253, 230 B; opening portion,comprising a resilient, cylindrical 215/355, 356, DIG, 3 stopper bodyprovided spatially from the upper end thereof with an annular grooveengageable with said [56] References Cited lug.

UNITED STATES PATENTS 1,415,908 5/1922 Tofting 215/356 X 6 Claims, 7Drawing Figures PATENTED AUG 51975 FIG.1

FIG. 4

FIG.6 FIG? FIG.

STOPIER FOR SEALING CONTAINERS This invention relates to a stopper forsealing a container such as an evacuated blood sampling tube or othertest tubes, and more particularly to a stopper for sealing a containerhaving a lug inwardly projecting at the edge of the container openingportion.

In the medical, biological or laboratory fields, various stoppers arewidely accepted which are used to seal containers such as an evacuatedblood sampling tube or other test tubes. Such a stopper should beprevented from unexpectedly disengaging from the container due to theaction of a pressure produced when the stopper is fitted or insertedinto the container or due to the increase in inner pressure resultingfrom the elevated temperature, and should be designed tightly to sealsaid container. To this end, the stopper has heretofore been subjectedto various contrivances.

In US Pat. No. 3,057,502, disclosure is made of the provision of aplurality of annular ribs in the outer periphery of the cylindricalhollow body of a stopper made of resilient plastic material. The outerperiphery of said annular rib constitutes the contacting surface withthe inner wall of a glass tube. The abovementioned publication furtherdiscloses that the annular rib surface is rough-finished in order toincrease the coefficient of friction between the inner wall of the glasstube and the stopper body.

The US. Pat. No. 3,136,440 relates to an elastomeric material-made selfsealing pierceable stopper for sealed container. Said stopper comprisesa cylindrical plug and an enlarged flange like head integrally formed atthe upper end thereof. In said plug and head is respectively formed arecess, and these two recesses are separated from each other by adiaphragm having a concave section at its upper portion and a convexsection at its lower portion. The outer diameter of said plug isslightly larger than the inner diameter of the container, therebyenabling said plug to tightly engage the container. Further, around theplug portion immediately adjacent the head there is formed acircumferential groove, which serves to minimize or relieve the stressesadjacent this portion of the plug resulting from the resistance of thehead of the stopper to compression of the plug when it is inserted inone opening in the container.

The prior art stoppers including those disclosed in said two UnitedStates Patents are so designed as to tightly engage the container at aposition in which the stopper is forced into the container.

It would not fully attain the purpose even if the stopper is once forcedinto the container. The stopper is usually repeatedly dismounted fromthe container in order to make tests on its contents. Under thecondition in which the stopper is maintained forced into the container,the air inside of the container is kept compressed. When, therefore, thestopper is pulled out from the container, it pops out therefrom withforce, and where the contents are liquid, they are likely to pop outsimultaneously with the disengagement of the stopper from the container.Further, after the stopper is dismounted, the liquid contents frequentlyadhere onto the inner wall surface of the container opening portion soas to decrease the force of friction between the stopper and thecontainer inner wall, which causes the stopper to gradually rise forready disengagement with the aid of the compressed air attained by thereinsertion of the stopper. As the result, a blood sampling tube used tomake a blood test, for example, had the drawback that blood was spilt orscattered to infect the tester. Particularly, a usual rubber stopper foruse with an evacuated blood sampling tube is so formed as to enlarge asmuch as possible the contacting portion of the stopper body surface withthe container inner wall mainly for the purpose of maintaining theevacuated state. For this reason, in such rubber stopper, the stopperbody except for its top end portion is so formed as to have a greaterouter diameter than the inner diameter of the container and, in order tomake a blood Sam pling needle readily pierceable into the stopper body,said stopper is formed at its both end portions with re cesses.Accordingly, where said stopper is reinserted into the container afteronce dismounted therefrom it is more decreased in fitted strength and ismore likely to raise the above-mentioned problems as compared with astopper for use with an ordinary wholly-tapered test tube.

Accordingly, an object of the invention is to provide an elastomericmaterial-made stopper for sealing a container which is prevented frombeing unexpectedly dismounted from the container once it is insertedthereinto.

Another object of the invention is to provide a stopper which is sodesigned as to seal the container without being dismounted therefromeven when raised due to the action of the compressed air within thecontainer produced when it is inserted thereinto.

According to the invention, there is provided an clastomeric stopper forsealing a container having an annular lug inwardly projecting at theedge of the container opening portion, comprising a cylindrical stopperbody and an anuular groove formed in said body spatially from the upperend thereof, said annular groove being engageable with said lug.

This invention can be more fully understood from the following detaileddescription when taken in conjunction with the accompanying drawing, inwhich:

FIG. 1 is a front view, partly exploded, of a stopper according to theinvention;

FIGS. 2 to 4 respectively are views illustrating the function of thestopper shown in FIG. 1; and

FIGS. 5 to 7 respectively are front views of other embodiments of thestopper according to the invention.

This invention will now be described by reference to the accompanyingdrawing. Referring to FIG. 1, a stop per according to the invention isdenoted by a reference numeral 1, and is made of resilient material suchas, for example, vulcanized rubber mainly consisting of butyl rubber,and presents a hardness of approximately 50 when its head portion ispressed from the lateral side thereof by a hardness tester according tothe Japanese Industrial Standard. The stopper 1 is fitted or insertedinto the opening portion of a container, for example, an evacuated bloodsampling tube 2, having an annular lug inwardly projecting at the edgeof the container opening portion, so as to seal said tube 2. Where thetube is made of glass, said lug may be the one which is necessarilyformed during heating of the container opening portion. In the case of atube having a capacity of 7 ml, the container is approximately 10.50 mmin inner diameter. The stopper 1 consists of a cylindrical stopper body3 tapered from its lower end portion 10 to its lowest end and having amaximum diameter of approximately 11.8 mm, and of an enlarged head 4formed integrally at the upper end of the body. In the lower end surfaceof the stopper body 3 and the upper end surface of the stopper head 4are formed recesses 5 and 6 so as to make a blood sampling needlereadily pierceable into the central portion of the stopper 1. When, inthis case, a blood sampling needle having a diameter of 0.08 mm ispierced at a speed of 20 mm/min., the piercing resistance accounts forapproximately'3.0 pounds as measured by Chatillon gauge. As abovedescribed, thestopper'body is designed to have a relatively elasticconstruction. The stopper body 3 is provided with an annular groove 9,spatially from the lower end of the stopper head 4 and at that portionof the outer circumference 7 of the body which is in the proximity ofthe'lower end portion 10 of the stopper body 3. The annular groove 9 hasa longitudinal section in which a line connecting a groove upper end E1on the side of the head 4 and the groove bottom 11 inclines toward saidbottom 11, and a line connecting together the other groove upper end E2and said groove bottom 11 is perpendicular to the central axis of thestopper body. The longitudinal section of the groove may be of any shapeif said groove has only to engage the container lug.

As hereinafter explained, when the stopper body 3 is gradually raisedfrom the position in which it is inserted into the blood sampling tube 2up to the upper end of the body, due to, for example, the inner pressureof the blood sampling tube, the annular groove 9 is engaged with thetube lug 2 to suppress the raising of the stopper body. The. groove isformed in the stopper body spatially from the upper end of the stopperbody, or preferably in the vicinity of the lower end of the body. Thegroove position is determined with the stopper hardness, containerlugheight, or groove depth synthetically taken into consideration. However,the container lug height should of course be limited to the range withinwhich the stopper is insertible into the container.

Referring to FIG. 2 to 4, the function of the stopper according to theinvention will now be described. The evacuated blood sampling tube 2prior to blood sampling is hermetically sealed by the stopper 1, and theinside of the tube is in an evacuated state. The stopper body 3 isinserted into the opening portion of the blood sampling tube 2 up to thelower end of the enlarged head 4. When the needle of a blood samplinginstrument is pierced into the stopper 1 thereby to perform bloodsampling, the reduction degree of pressure within the tube is decreasedso that the stopper is brought to a manually dismountable state.

Where the general test on blood (the erythrocyte number, leukocytenumber or hematocrit value) is carried out, a lot of blood is sampled inthe evacuated blood sampling tube 2 previously charged with a bloodanticoagulant. The stopper 1 is then dismounted (see FIG. 2) from thetube and said blood is discharged therefrom exactly to an extentnecessary for the test on one item, and the stopper 1 is again inserted(see FIG.

3). The stopper-inserted tube is set on a blood mixing per body 3 andthe inner wall of the blood sampling tube 2, so that the stopper becomesliable to disengage from the tube. For this reason, even when thestopper 1 is again forced into the tube 2 and the stopper body 3issufficiently inserted into the tube up-to the lower end of the stopperhead 4, said sufficient insertion so actsas to increase the pressure ofthe interior 8 of the tube, and said increased pressure so acts as toraise the stopper by degrees. At this time, as shown in FIG. 4, theannular groove 9 formed in the stopper body 3 is tightly engaged withthe annular lug P of the blood sampling tube 2 fully to stop the upwardmovement of the stopper 1, thereby preventing the disengagement of thestopper from the tube. Further, also when the blood sampling tube islaid or upset for mixing its charged mass, it is maintained sealedwithout causing the mass to be spilt therefrom. When this is viewed fromthe inner pressure condition of the tube, the rise of the stopper body 3decreases the tube inner'pressure previously kept relatively increasedby the insertion of the stopper body 3 into the tube. Upon disengagementof the stopper, therefore, the mass is prevented from forcibly poppingout from the tube.

The provision of the annular groove in close proximity to the lower endportion 10 of the stopper body 3, when the stopper 1 is inserted, causessaid ring-shaped lower end portion 10 to be bent in the oppositedirection to the direction of the stopper insertion, thus to facilitatethe stopper insertion.

FIGS. 5 to 7 respectively illustrate other embodiments of the stopperaccording to the invention. FIG. 5 shows a stopper wherein the lower endportion of the stopper body 3 is largely tapered; and a ring-shapedprotrusion 13 having its outer circumference'made substantially flushwith the outer circumference of the stopper body 3 is formed on theintermediate portion of the outer circumference of said tapered section,whereby an annular groove is defined by said ring 13 with the taperedplane above it. FIG. 6 shows another stopper having a similarconstruction to that shown in FIG. 1, in which the lower end portion 15of the stopper body 3 presents a tapered curved surface. FIG. 7 showsanother stopper having an annular groove 16 formed in the centralportion of the outer circumference of the stopper body.

The preceding embodiments referred to the case where the stopper of theinvention is applied to the evacuated blood sampling tube, but theabovementioned problems are not raised only about said tube andtherefore the stopper of the invention is also applicable to containerssuch as ordinary test tubes.

The use of the stopper according to the invention enables the 'reliableprevention of infection due to the stopper popping out or due to thecharged mass being scattered upon disengagement of the stopper. Theintrahospital infection such as the infection of serumcholangeitis orsyphilis with a blood-tester via a patients blood scattered, forexample. in a clinical examination room or laboratory room has recentlybecome an important problem. The use of the stopper according to theinvention enables the complete prevention of such intrahospitalinfection. Accordingly, the stopper of the invention prevents aprominent effect when put to practical use.

What is claimed is:

1. An elastomeric stopper for sealing a container having an annular luginwardly projecting at the edge of the container opening portion,comprising a cylindrical stopper body and an annular groove formed insaid body spatially from the upper end of the stopper body, whereby saidstopper inserted with its groove below the lug of the container may bepushed up with the pressure built up in the container during theinsertion of the stopper until the groove engages the lug and becomesfixed tight in the container.

2. A stopper according to claim 1, wherein the stopper body is taperedat its lower end portion, and said annular groove is defined by aring-shaped protrusion formed on the intermediate portion of the outercircumference of said tapered section and having its outer circumferencemade substantially flush with the outer circumference of the stopperbody and the tapered plane positioned above said ring-shaped protrusion.

3. A stopper according to claim 1, wherein said annular groove is formedadjacent to the lower end of said stopper body.

4. An elastomeric stopper for sealing a container having an annular luginwardly projecting at the edge of the container opening portion,comprising a cylindrical hollow stopper body whose lower end portion istapered, an enlarged head formed integrally at the upper end of saidbody and having a recess at its upper end, and a ring-shaped protrusionwhich is formed on the intermediate portion of the outer circumferenceof said tapered end portion of said body, has its outer circumferencemade substantially flush with the outer circumference of the stopperbody and constitutes an annular groove with the tapered plane of saidstopper body po' sitioned above it, whereby said stopper inserted withits groove below the lug of the container may be pushed up with thepressure built up in the container during the insertion of the stopperuntil the groove engages the lug and becomes fixed tight in thecontainer.

5. An elastomeric stopper for sealing a container having an annular luginwardly projecting at the edge of the container opening portioncomprising a cylindrical stopper body having a tapered lower end, anenlarged head formed integrally on the upper end of said body, centralrecesses in said body and head whereby the stopper presents a closurebarrier in its central portion of substantially less longitudinaldimensions than the overall length of the stopper, and a single annulargroove on said stopper body adjacent the lower end thereof, said groovebeing defined by a first plane which extends radially into the stopperbody and a second plane which extends into the stopper body above saidfirst plane at an acute angle to said first plane and intersects saidfirst plane within the stopper body.

6. A blood sampling container comprising a sampling tube having a closedend and an open end, an annular lug inwardly projecting at the edge ofsaid open end and an elastomeric stopper comprising a cylindricalstopper body having a tapered lower end, an enlarged head formedintegrally on the upper end of said body, the lower end of said headpresenting a flat ledge extending radially beyond said stopper body,central recesses in said body and head whereby the stopper presents aclosure barrier in its central portion of substantially lesslongitudinal dimension than the overall length of said stopper and asingle annular groove on said stopper body adjacent the lower endthereof, said groove having a depth substantially corresponding to theradial dimension of said annular lug. said stopper extending into theopen end of said tube with said flat ledge of the stopper in contactwith said edge of the open end sealing the container by engagement ofsaid lug with a portion of said stopper body above said annular groove.

1. AN ELASTOMERIC STOPPER FOR SEALING A CONTAINER HAVING AN ANNULAR LUGINWARDLY PROJECTING AT THE EDGE OF THE CONTAINER OPENING PORTION,COMPRISING A CYLINDRICAL STOPPER BODY AND AN ANNULAR GROOVE FORMED INSAID BODY SPATIALLY FROM THE UPPER END OF THE STOPPER BODY, WHEREBY SAIDSTOPPER INSERTED WITH ITS GROVE BELOW THE LUG OF THE CONTAINER MAY BEPUSHED UP WITH THE PRESSURE BUILT UP IN THE CONTAINER DURING THEINSERTION OF THE STOPPER UNTIL THE GROOVE ENGAGES THE LUNG AND BECOMESFIXED TIGHT IN THE CONTAINER.
 2. A stopper according to claim 1, whereinthe stopper body is tapered at its lower end portion, and said annulargroove is defined by a ring-shaped protrusion formed on the intermediateportion of the outer circumference of said tapered section and havingits outer circumference made substantially flush with the outercircumference of the stopper body and the tapered plane positioned abovesaid ring-shaped protrusion.
 3. A stopper according to claim 1, whereinsaid annular groove is formed adjacent to the lower end of said stopperbody.
 4. An elastomeric stopper for sealing a container having anannular lug inwardly projecting at the edge of the container openingportion, comprising a cylindrical hollow stopper body whose lower endportion is tapered, an enlarged head formed integrally At the upper endof said body and having a recess at its upper end, and a ring-shapedprotrusion which is formed on the intermediate portion of the outercircumference of said tapered end portion of said body, has its outercircumference made substantially flush with the outer circumference ofthe stopper body and constitutes an annular groove with the taperedplane of said stopper body positioned above it, whereby said stopperinserted with its groove below the lug of the container may be pushed upwith the pressure built up in the container during the insertion of thestopper until the groove engages the lug and becomes fixed tight in thecontainer.
 5. An elastomeric stopper for sealing a container having anannular lug inwardly projecting at the edge of the container openingportion comprising a cylindrical stopper body having a tapered lowerend, an enlarged head formed integrally on the upper end of said body,central recesses in said body and head whereby the stopper presents aclosure barrier in its central portion of substantially lesslongitudinal dimensions than the overall length of the stopper, and asingle annular groove on said stopper body adjacent the lower endthereof, said groove being defined by a first plane which extendsradially into the stopper body and a second plane which extends into thestopper body above said first plane at an acute angle to said firstplane and intersects said first plane within the stopper body.
 6. Ablood sampling container comprising a sampling tube having a closed endand an open end, an annular lug inwardly projecting at the edge of saidopen end and an elastomeric stopper comprising a cylindrical stopperbody having a tapered lower end, an enlarged head formed integrally onthe upper end of said body, the lower end of said head presenting a flatledge extending radially beyond said stopper body, central recesses insaid body and head whereby the stopper presents a closure barrier in itscentral portion of substantially less longitudinal dimension than theoverall length of said stopper and a single annular groove on saidstopper body adjacent the lower end thereof, said groove having a depthsubstantially corresponding to the radial dimension of said annular lug,said stopper extending into the open end of said tube with said flatledge of the stopper in contact with said edge of the open end sealingthe container by engagement of said lug with a portion of said stopperbody above said annular groove.